In motor vehicles, oil pressure transducers have previously utilized a construction with a two-part housing capturing a flexible diaphragm member therebetween. The diaphragm is movable in response to the pressure of engine oil in the lubrication system so as to operate warning switch means. The switch means are connected into a warning circuit so that when oil pressure falls below a desired minimum level, a warning light or the like is activated. The two-part housing is joined together about the aforementioned diaphragm by means of a crimping operation in which an edge portion of one housing portion is rolled or turned over in a mechanically deforming operation about a flange portion of the other housing part.
Previous oil pressure transducers have utilized a base housing portion including a threaded male end portion adapted to be received in a threaded aperture of the engine which fluidly communicates with the lubrication system of the engine. The prior transducers have utilized housing bases with relatively thick walls made by turning and cutting a solid metal cylinder on a screw machine or the like. This produces a relatively thick walled and heavy part. Obviously, another disadvantage of this type of housing is the high cost in machining the housing on the aforementioned screw machine. It has been found that a base housing can be easily formed without machining and with thin walls by cold forming. However, this type of housing lacks a relatively thick wall or a large diameter circumferential surface such as a hexagonal surface which can be utilized to rotate the transducer by a wrench or the like. The subject application describes a housing with a thin walled portion and with a desirable circumferential surface formed thereon defining a wrenching portion. The wrenching portion is formed by a molded elastomeric material or the like and has desirable wrenching surfaces formed thereon. The wrenching portion may be manufactured separately and subsequently joined to the housing by a press fit or by adhesives or the wrenching portion may be mold formed about the base housing.
Therefore, an object and advantageous feature of the subject transducer is the provision of a hollow base housing which is adapted to be threadably and insertably mounted on an engine in fluid communication with the engine lubrication system, the base being of desirably light and inexpensive thin walled and easily formed material, the base having an annularly shaped wrenching portion formed thereabout to rotate the transducer by use of an installation tool without crushing the housing. A further advantageous feature and object of the subject application is the provision of an oil level transducer with a hollow base housing portion adapted for threadably securing the base to an engine and with the base of desirably thin walled and easily formed material encircled by a wrenching portion of diverse material.
Other advantageous features of the subject transducer will be more readily apparent from a reading of the following Detailed Description of a Preferred Embodiment, reference being had to the accompanying drawings in which preferred embodiments are illustrated.